Flexible graphite reinforced with a metal or fiberglass core is currently used as a sealing gasket for the engine block and cylinder head in an automobile engine. A laminate of flexible graphite and metal may be physically formed by impressing a flexible graphite facing over a metal sheet containing multiple tangs which perforate the facing to mechanically interlock the laminate. Alternatively the laminate may be formed by adhesively bonding flexible graphite to the metal core. The adhesive composition must form an intergral bond between the flexible graphite and core material which is chemically and thermally stable and is impervious to organic solvents such as methylethyl ketone. Moreover, the procedure for laminating flexible graphite to a sheet of metal such as steel must be carried out in a manner which will not cause the flexible graphite to blister. In a corresponding U.S. patent application Ser. No. 709214 filed Jun. 3, 1991, a method to form a flexible graphite laminate is disclosed using a phenolic resin adhesive composition which is cured off-line under controlled conditions of temperature and time to avoid surface blistering and delamination.
A method of fabricating a flexible graphite metal core laminate in which the flexible graphite is cohesively bonded to the metal core through an epoxy resin in a continuous on-line operation without a post treatment cure is preferable to all other currently known fabrication techniques.